Armrest and armrest mechanism

ABSTRACT

An armchair mechanism that includes a toothed pawl and cam mechanism which allows the armrest to rotate in an arc greater than 90 degrees and into a first angular position. The armchair mechanism further includes a lockout member which locks the armrest in a design position and a stowed position. During a first angular portion of movement along the rotation arc, the armrest can be secured in several discrete angular positions whereas movement of the armrest in the first angular position is one-way so that the armrest can only rotate upward and be secured in any one of the several discrete angular positions.

FIELD OF THE INVENTION

The present invention relates generally to an adjustment mechanism and an armrest for using the adjustment mechanism, and more particularly, to an armrest adjustment mechanism and armrest for use within a vehicle.

BACKGROUND OF THE INVENTION

Vehicle seats, especially those located in the rear of vans or mini-vans, often have an armrest pivotable from a generally vertical, stowed position to a generally horizontal, in-use design position. When in the stowed position, the armrest does not hinder movement into or out of the seat and facilitates folding the backrest of the seat to allow the seat to be more easily removed from the vehicle or stored within the vehicle.

In some applications, it is desirable for the armrest to be adjustable to one of many fixed positions between the design position and the fully upright stowed position. A mechanism for implementing such a function in an armrest is shown in U.S. Pat. No. 6,106,068, issued to Marc Lefevere.

The armrest mechanism shown in that patent uses two ratchets. When in contact, the ratchets can be rotated in only one direction. After the two ratchets are rotated a predetermined amount, one of the two ratchets is then retained in a locking mechanism separate from the other ratchet, thereby allowing the armrest to be rotated in the opposite direction. When the ratchets have been rotated relative to each other a predetermined amount, the latch is released, and the two ratchets are once again placed in contact.

One problem with such a mechanism is that the latch may become worn, allowing premature contact between the two ratchets. Additionally, the latch may not reliably release the ratchet, requiring an additional force to move the armrest into the desired position.

An improved armrest mechanism allowing for adjustment of an armrest into multiple positions between the design position and the stowed position is highly desirable.

SUMMARY OF THE INVENTION

The improved armrest mechanism utilizing this invention allows an armrest to travel in an arc of somewhat more than ninety degrees. During a first angular portion of the arc, the armrest can be secured in several discrete angular positions. Movement of the armrest in the first portion is “one way” (e.g., counterclockwise)—it can be rotated only upward but also allowing it to be secured at one of several discrete positions. If the armrest is rotated beyond the first angular portion by several degrees, then the armrest can either be rotated further to the stowed position or it can be returned to the design position. If secured in the stowed position, the armrest can be rotated further in the same counterclockwise direction, and the armrest is then released so as to be rotated clockwise for return to the design position. Once the armrest is released from the stowed position, the armrest cannot be returned to the stowed position unless the armrest has been moved several degrees toward the design position.

To accomplish this movement, the armrest mechanism utilizes a combination of a toothed pawl with a cam. A lockout member is provided with a design position portion and a stowed position portion. Both portions are toothed. When rotated,

FIG. 7 shows the armrest mechanism in the design position.

FIGS. 8-10 show the armrest mechanism as it rotates counterclockwise from the design position to the stowed position.

FIG. 11A-12 shows the armrest mechanism entering the stowed position.

FIGS. 13A-14B show the armrest mechanism being moved from the stowed position counterclockwise prior to movement in the clockwise.

FIGS. 15A-18 show the armrest mechanism 18 rotated in the clockwise direction to the design position.

DESCRIPTION OF THE INVENTION

For the purposes of this description, the armrest moves counterclockwise from the design position to the stowed position. Obviously, the armrest could rotate clockwise from the design position to the stowed position

FIG. 1A shows armrest 2 attached to a seat 4 when the armrest is in the design position. Arc 6 shows the range of movement of armrest 2. Arc 6 is divided into angular portion I, angular portion II, and angular portion III. The armrest may be rotated counterclockwise to the stowed position, shown in FIG. 1B.

In angular portion I, user can position the armrest at discrete angles between the design position and the stowed position. The armrest resists any movement in the clockwise direction, although the armrest can be rotated in the counterclockwise direction. When the armrest is moved into angular portion II, the armrest can be moved either to the stowed position or the design position. If the armrest is moved to the stowed position, armrest 2 is rotated to the end of angular portion III in order to release armrest 2 from the stowed position. After the armrest is released, the armrest can be moved to angular portion II and then returned to the design position. When rotating in the clockwise direction, the armrest will not lock into any position other than the design position.

FIG. 2 is a perspective view of the armrest assembly 14. Armrest assembly 14 has bolt 16 for insertion into the seat. Armrest mechanism 18 is contained within armrest housing 20.

FIG. 3 is a side view of the armrest assembly 14. FIG. 4 is an exploded view of armrest assembly 14. FIG. 5 is a view of the armrest assembly 14, and more specifically armrest mechanism 18, taken along section B-B of FIG. 3.

The explanation of the components of armrest assembly 14 is with reference to FIGS. 4 and 5 conjointly.

Bolts 50 are used to retain right cover 52 to left cover 54. Plate cover sides 56, 58 are used to armrest mechanism 18. Cylinder pin 17 attaches bolt 16 to lockout mechanism 68. Damper 64 is placed around bolt 16. Damper springs 60, 62 provide some resistance to the motion of the armrest in either the clockwise or counterclockwise direction. Spring blade 66 is returns the main sector bypass 72 to its first position as shown in FIG. 7.

Lockout member 68 is a generally cylindrical arrangement enabling the various feature of the armrest assembly. Stowed bypass 70 and main bypass 72 interact with lockout member 68 to enable the functionality of the bypass mechanism. Pawl 74 is attached to plate cover sides 56, 58 by way of pawl axle 76. Pawl axle 76 rests within pawl axle holes 78, 80. Pawl spring 82 urges pawl 74 into contact with lockout member 68. Pawl 74 includes pawl pin 75 and pawl teeth 100.

FIG. 6 shows lockout member 68 in more detail. Lockout guide 80 is circular, with portions cut from the perimeter to form lockout guide portion 90. As pawl pin 75 travels within lockout guide portion 90, pawl 74 is rotated on pawl axle 76, thereby causing pawl teeth 100 to engage or disengage from lockout teeth 92.

The operation of armrest mechanism 18 will be shown with reference to FIGS. 7-18. FIG. 7 shows the armrest mechanism 18 in the design position. Spring 82 urges pawl teeth 100 of pawl 74 against first teeth portion 102 of lockout member 68. Pawl pin 75 rests between main bypass guide portion 104 of main bypass 72 and wall 106 of lockout member 68. Main bypass 72 is attached to lockout member 68 by way of pin 108. Thus, main bypass 72 can rock from a first position to a second position. Similarly, stowed bypass 70 is attached to lockout member 68 by way of pin 110. Stowed bypass 70 can also rock from a first position to a second position.

FIG. 8 shows armrest mechanism 18 rotating counterclockwise from the design position. Spring 82 continues to urge pawl teeth 100 against first teeth portion 102. Pawl pin 75 goes under main bypass stop 104, thereby lifting main bypass 72. Main bypass 72 pivots about pin 108, and flexes spring blade 66. The interaction of pawl pin 75 with main bypass 72 causes first teeth portion 102 and pawl teeth 100 to remain firmly engaged while providing a user with tactile feedback.

First teeth portion 102, and pawl teeth 100 prevent rotation of armrest mechanism 18 in the clockwise direction.

FIG. 9 shows pawl pin 75 encountering slope 110 of lockout guide portion 90 while the armrest is rotating in the counterclockwise direction. Slope 110 lifts pawl teeth 100 away from first teeth portion 102.

FIG. 10 shows pawl pin 75 after being lifted away from first teeth portion 102 by lockout guide portion 90. Armrest mechanism 18 can be rotated either in the clockwise or counterclockwise direction.

FIG. 11A shows pawl pin 75 entering under the first detail 117 of stowed bypass 70, moving stowed bypass 70. FIG. 11B shows pawl pin 75 entering the first trough 120.

FIG. 12 shows pawl pin 75 under stop 122. Pawl teeth 100 are fully engaged with second teeth portion 120. In this position, armrest mechanism 18 can be rotated only in the counterclockwise direction. Armrest mechanism 18 is in the stowed position.

In FIG. 13A, armrest mechanism 18 has been rotated further in the counterclockwise direction. Pawl pin 75 pushes the ramp portion 134 of the third detail thereby pushing stowed bypass 70 down. FIG. 13B shows stowed bypass 70 in the bypass position.

FIG. 14A shows pawl pin 75 lifted by ramp portion 134. Stowed bypass 70, like main bypass 72 rotates about pin 130. This results in pawl pin using a different path on the up/lock stroke than on the down/release stroke. When pawl pin 75 pushed on the third detail of the stowed bypass 70, the force creates an indication to the user that the armrest can now be rotated in the clockwise direction.

FIG. 14B shows pawl pin 75 on the top of first detail 122. At this time, movement of the armrest can occur in the clockwise direction.

FIGS. 15A and 15B show the armrest mechanism 18 as the armrest is rotated in the clockwise direction. Pawl pin 75 moves over the top of the first detail 122 toward plateau 160. Therefore, the teeth do not engage and allow the armrest to be moved away from the stowed position.

In FIG. 16, pawl pin 75 is traveling on plateau 160 of lockout guide portion 90. Pawl teeth 100 are thus kept away from lockout member 68.

FIG. 17 shows the pawl pin 75 going over stop 104. In FIG. 18, pawl pin 75 has reached the end of stop 104. Spring 82 urges pawl pin 75 between stop 104 and wall 106.

At this position, the armrest mechanism is near its original starting position shown in FIG. 7.

The above description is of the preferred embodiment. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents. Any references to claim elements in the singular, for example, using the articles “a,” “the,” or “said,” is not to be construed as limiting the element to the singular. 

1: Armrest mechanism which comprises: a toothed pawl and cam mechanism which allows an armrest to rotate in an arc greater than 90 degrees and into a first angular position; and a lockout member which locks the armrest in a design position and a stowed position, wherein during a first angular portion of movement along the rotation arc, the armrest can be secured in several discrete angular positions whereas movement of the armrest in the first angular position is one-way so that the armrest can only rotate upward and secured in anyone of the several discrete angular positions. 